Sunscreens are still shrouded in misunderstandings and myths, for example, we often buy a high protection factor sunscreen (SPF), but put on too little too irregularly to get the most benefit. Our biggest mistake is that we think we are protected, so better understanding sunscreen’s limitations is important.
The gap in our understanding of sunscreen and sun damage is glaring if you are in the business, because you look at the effects of poor sunscreen application all the time: wrinkles, sunspots, age spots and pigmentation problems.
Sunscreen is an adjunct to our natural defences, with physical sunscreens designed to scatter and reflect UV radiation, while chemical sunscreen absorbs and transform UV radiation to heat. We typically look for a sunscreen that isn’t irritating, isn’t sticky and smells nice, and it would be even better if the sunscreen formed an even layer over the skin, was affordable, and was composed of approved ingredients. Sadly, this product doesn’t exist. There is always a trade-off.
No sunscreen provides complete protection from ultraviolet radiation. Each ingredient has unique abilities, with the goal to fill in as many ingredient gaps as possible to provide as much protection as possible. Sunscreen is not a substitute for protective clothing and avoiding the sun at its worst.
Rubbing sunscreen into the skin isn’t ‘better’, and having an even layer of sunscreen is impossible to achieve. SPF is also problematic, since SPF of 30 blocks 97 per cent of UVB rays, while an SPF of 15 blocks 93 per cent, and an SPF of 45 only blocks 98 per cent. It’s not 100 per cent, ever. The SPF rating is also only UVB rays – SPF does not address UVA rays. UVC rays are currently not protected for at all, but are increasingly being found on earth (as opposed to hardly reaching into our atmosphere).
Why are sunscreens so limited?
Several sunscreen ingredients are incompatible. For example UVB-blocking octyl methoxycinnamate doesn’t work when combined with UVA-blocking agents like avobenzone. The perfect sunscreen is hard to make, so we make do with what we’ve got and what ingredients work together well enough to make a decent, usable product. Usually what happens is that there is a tradeoff between SPF and how nice the product is to use. High SPF products have more sticky oils in them, making them less enjoyable to use. A modest SPF may be the best choice not because it’s the best sunscreen, but because people are more likely to use it if they enjoy using it.
The point here is that understanding sunscreen is not as easy as we might think, and the best sunscreens may actually be the least enjoyable to use. Do your best!
Want expert advice?
We can help.